| JY Offshore Ltd | Administrative & support | 2026 |
| Jyve Management Limited | Wholesale & retail | 2014 |
| JZV Limited | Real estate | 2025 |
| K & K Business Consult Ltd | Extraterritorial | 2010 |
| K & S Commercial Cleaning Ltd | Administrative & support | 2014 |
| K a H Body Repairs Limited | Wholesale & retail | 2011 |
| K C G Engineering Limited | Manufacturing | 2012 |
| K Imba Holdings Ltd | Real estate | 2025 |
| K R Developments (Manchester) Ltd | Real estate | 2024 |
| K Rowcroft Ltd | Construction | 2017 |
| K Salon Ltd | Other services | 2023 |
| K&F Renovations Ltd | Real estate | 2025 |
| K&K Supreme Group Limited | Administrative & support | 2025 |
| K'S Chemists Limited | Wholesale & retail | 2002 |
| K'S Renovation & Engineering Ltd | Construction | 2025 |
| K-9 Black Sabre Security Ltd | Agriculture & fishing | 2021 |
| K-Michael Ltd | Health & social care | 2024 |
| K.COLLECTION27 Ltd | Wholesale & retail | 2024 |
| K.L. Import Export Limited | Wholesale & retail | 1987 |
| K23EMOTO Limited | Wholesale & retail | 2023 |
| K9CHASE Ltd | Administrative & support | 2025 |
| KA Beauty (MCR) Ltd | Other services | 2023 |
| KA Solutions Ltd | Other services | 2023 |
| KA2B Ltd | Transport & logistics | 2026 |
| Kaabo Limited | Professional & scientific | 2022 |
| Kadp Limited | Real estate | 2025 |
| Kaerley Estates Limited | Real estate | 2020 |
| Kaha Healthcare Services Ltd | Health & social care | 2022 |
| Kahan Estates Ltd | Real estate | 2018 |
| Kahn's Estates Limited | Real estate | 2026 |
| Kaijah Ltd | Hospitality | 2024 |
| Kaizaza Ltd | Wholesale & retail | 2025 |
| Kalamata Ltd | Manufacturing | 2018 |
| Kaleidoscope Investments (NW) Limited | Real estate | 2021 |
| Kalivia UK Ltd | Professional & scientific | 2025 |
| Kallos Cafe & Wine Bar Limited | Hospitality | 2023 |
| Kalto Ltd | Other services | 2025 |
| KAM Motion Limited | Manufacturing | 2015 |
| Kamo-Rites Limited | Wholesale & retail | 2025 |
| Kane Roofing Limited | Construction | 2018 |
| Kanki Investement Limited | Households | 2017 |
| Kanmar Trustees Limited | Administrative & support | 1968 |
| Kanzbahr Lines UK Ltd | Transport & logistics | 2019 |
| Kapukai Investments Limited | Real estate | 2015 |
| KAR Automotive Services Ltd | Wholesale & retail | 2016 |
| KARA24 Ltd | Health & social care | 2025 |
| Karaya Group Ltd | Wholesale & retail | 2021 |
| Karen Rose Ltd | Real estate | 2004 |
| Karigarwala Ltd | Wholesale & retail | 2025 |
| Karka Capital Limited | Real estate | 2025 |
| Karmen Funding Limited | Financial services | 2013 |
| Karnon Ltd | Wholesale & retail | 2021 |
| Karpe Noctem Limited | Financial services | 2022 |
| Karpeediem Limited | Construction | 2019 |
| Kashcow Limited | Financial services | 2014 |
| Kashmir Justice Foundation Centre | Health & social care | 2020 |
| Kasmo Construction Ltd | Construction | 2024 |
| Kate Land Creative Ltd | Information & communication | 2026 |
| Kathryn Hughes Ltd | Information & communication | 2017 |
| Katie Alex Promotions Limited | Other services | 2022 |
| KAY Audio Production Ltd | Information & communication | 2025 |
| KAY Cleaning Limited | Administrative & support | 2022 |
| KAY Leigh & Zachary Ltd | Professional & scientific | 2022 |
| KAY MIL Limited | Health & social care | 2025 |
| KAY Print and Design Ltd | Administrative & support | 2012 |
| Kaya's Admin and Beauty Ltd | Administrative & support | 2025 |
| Kaya's Expert Reports Limited | Financial services | 2024 |
| Kayleb Property Ltd | Real estate | 2023 |
| Kayline Properties Ltd | Real estate | 2019 |
| Kayo Logistics Limited | Transport & logistics | 2025 |
| Kaytek Purchasing Limited | Wholesale & retail | 2009 |
| Kaytons Investments Ltd | Real estate | 2024 |
| Kaytons Ltd | Administrative & support | 2011 |
| KBO Krest Ltd | Real estate | 2026 |
| KC Barbers Ltd | Other services | 2026 |
| KD Bike Shop Ltd | Manufacturing | 2025 |
| KD Filling Ltd | Other services | 2025 |
| KDF Estate Ltd | Real estate | 2024 |
| KEBABS2GO T/A Bella Pizza Ltd | Hospitality | 2025 |
| Kechi’S Kitchen Limited | Hospitality | 2026 |
| Keighley Securities 2 Limited | Real estate | 2023 |
| Keighley Securities Limited | Real estate | 2023 |
| Keilder Limited | Information & communication | 1999 |
| Keitec Solutions Limited | Information & communication | 2017 |
| Kellogg's (Great Britain) Pension Trustee Limited | Administrative & support | 2020 |
| Kells North West Limited | Water & waste | 1994 |
| Kempson Consulting Services Limited | Administrative & support | 2013 |
| KEN Private Carer Services Ltd | Health & social care | 2026 |
| Kennedy Estates Ltd | Extraterritorial | 2003 |
| Kent LEP 1 Limited | Construction | 2008 |
| Kerem Holdings Limited | Real estate | 2025 |
| Keren Logistics Limited | Transport & logistics | 2023 |
| Kerestier Ltd | Real estate | 2016 |
| Kerestir Travel Ltd | Administrative & support | 2023 |
| Kernsview Ltd | Real estate | 2024 |
| Kersa Group Ltd | Education | 2026 |
| Kersal Mews Management Company Limited | Households | 2016 |
| Kersal Ventures Ltd | Real estate | 2018 |
| Kesser Torah Ltd | Administrative & support | 2022 |
| KEST1 Limited | Real estate | 2025 |